The Redragon M808 Storm is equipped with the PixArt PAW3327. According to specifications, the 3327 is capable of up to 6200 CPI, as well as a maximum tracking speed of 220 IPS, which equals 5.59 m/s. Through interpolation, resolution has been doubled to 12,400 CPI. Out of the box, five pre-defined CPI steps are available: 500, 1000, 2000, 3000, and 6200 CPI.
CPI Accuracy
"CPI" (short for counts per inch) describes the number of counts registered by the mouse if it is moved exactly an inch. There are several factors (firmware, mounting height of the sensor not meeting specifications, mouse feet thickness, mousing surface, among others) which may contribute to actual CPI not matching nominal CPI. It is impossible to always achieve a perfect match, but ideally, nominal and actual CPI should differ as little as possible. In this test I'm determining whether this is the case or not. However, please keep in mind that said variance will still vary from unit to unit, so your mileage may vary as well.
I've restricted my testing to the four most common CPI steps, which are 400, 800, 1600, and 3200. As you can see, deviation is really inconsistent. 400 and 3200 CPI are way off, 1600 CPI a bit off, and 800 CPI is spot on. An average result overall. In order to account for the measured deviation, steps of 400, 800, 1600, and 3400 CPI have been used during testing.
Motion Delay
"Motion delay" encompasses all kinds of sensor lag. Any further sources of input delay will not be recorded in this test. The main thing I'll be looking for in this test is sensor smoothing, which describes an averaging of motion data across several capture frames in order to reduce jitter at higher CPI values, increasing motion delay along with it. The goal here is to have as little smoothing as possible. As there is no way to accurately measure motion delay absolutely, it can only be done by comparison with a control subject that has been determined to have the lowest possible motion delay. In this case the control subject is a G403, whose 3366 has no visible smoothing across the entire CPI range.
First, I'm looking at two xCounts plots—generated at 800 and 3200 CPI—to quickly gauge whether there is any smoothing, which would be indicated by any visible "kinks." The 3327 doesn't have fixed framerate levels, which has no framerate transitions show up in these two xCount graphs. However, we can see that the tracking is quite clean, with very little jitter. Let us take a look at the xSum plots to determine motion delay.
Here, we're looking at three xSum plots, generated at 800, 3200, and 6200 CPI. The line further to the left denotes the sensor with less motion delay. At 800 CPI, motion delay is 1 ms. It's unclear whether this is due to smoothing or some other delay. 3200 CPI shows a motion delay differential of roughly 2.5 ms. Finally, at 6200 CPI, motion delay is 4 ms. The transition points are 2800/2900 CPI and 5300/5400 CPI (nominal values).
Speed-related Accuracy Variance (SRAV)
What people typically mean when they talk about "acceleration" is speed-related accuracy variance (or SRAV for short). It's not about the mouse having a set amount of inherent positive or negative acceleration, but about the cursor not traveling the same distance if the mouse is moved the same physical distance at different speeds. The easiest way to test this is by comparison with a control subject that is known to have very low SRAV, which in this case is the G403. As you can see from the plot, no displacement between the two cursor paths can be observed, which confirms that SRAV is very low.
Perfect Control Speed
Perfect Control Speed (or PCS for short) is the maximum speed up to which the mouse and its sensor can be moved without the sensor malfunctioning in any way. I've only managed to hit a measly 4.0 m/s (which is within the proclaimed PCS range), at which no sign of the sensor malfunctioning can be observed.
Polling Rate Stability
All four available polling rates (125 Hz, 250 Hz, 500 Hz, and 1000 Hz) look nice and stable.
Paint Test
This test is used to indicate any potential issues with angle snapping (non-native straightening of linear motion) and jitter, along with any sensor lens rattle. As you can see, no issues with angle snapping can be observed. No jitter is visible at 800 and 1600 CPI. 3200 CPI shows minor jitter, while 6200 CPI shows major jitter. If the measured motion delay is due to smoothing, it's not doing a great job. Lastly, no sensor lens rattle can be observed.
Lift-off Distance
The M808 Storm does not support adjusting LOD. At the default setting, LOD is low as the sensor does not track at a height of 1 DVD (<1.2 mm). Keep in mind that LOD may vary slightly depending on the mousing surface (pad) it is being used on.
Click Latency
Since mechanical switches are being used for the buttons in most computer mice, debouncing is required in order to avoid unintended double clicks. Debouncing typically adds a delay (along with any potential processing delay), which shall be referred to as click latency. As there is no way to measure said delay directly, it has to be done by comparing it to a control subject, which in this case is the Logitech G100s. Using the latest firmware, click latency has been measured to be roughly +10.9 ms compared to the SteelSeries Ikari, which is considered as the baseline with 0 ms. Please keep in mind that the measured value is not the absolute click latency. Comparison data comes from this thread as well as my own testing, using qsxcv's program.